Visualization and measurement are key components of geospatial data. Imaging rovers reduce the cost of data acquisition while providing more information than ever before.
The year 2013 witnessed the emergence of several important new technologies. Unmanned aerial systems (UAS) and new solutions for field imaging dominated industry headlines—and rightfully so. They represent the next generation approaches to gathering accurate field data and delivering information across an expanded set of users and applications.
These advances shared an important common thread: They all utilize digital imaging as a primary way to capture raw information. While we’ve seen cameras used for terrestrial data collection for several years, 2013 saw new software and field equipment combine to produce integrated solutions to capture and utilize georeferenced images. In addition to its role in documentation and visualization, imaging now serves as an important tool for precise measurement.
This explosive growth in imaging and terrestrial photogrammetry will continue, led by new technologies such as the Trimble V10 Imaging Rover, a compact integrated camera system that captures 360-degree digital panoramic images. Typically used in conjunction with a GNSS or optical positioning system, the Trimble V10 delivers georeferenced data for visualization and measurement of a project site. In this column, we’ll look at some specific applications and approaches that illustrate how this new generation of terrestrial photogrammetry is transforming the work of geospatial professionals.
Filling the White Space of Geospatial Information
The need for geospatial data covers a wide continuum of precision and data types. Applications such as engineering surveys and as-builts require dense sets of precise measurements and 3D positions. Mapping can use lower-precision positions but often needs more detail on objects and features. And asset management may require high levels of precision and details on features and attributes. In between these examples, the continuum is occupied by applications that require varying combinations of precision and information density.
For example, consider a survey of assets in a utility plant, where georeferenced panoramas, gathered as part of the existing data collection workflow, provide a new deliverable that serves a new group of consumers of geospatial information. Some data for plant engineering and asset management can be gathered using low-density scans and individual points collected using a Trimble VX spatial station. But panoramic images provided by the Trimble V10 bring a deeper level of information. The panoramic photos are very useful to facility maintenance teams, who want to see pictures of everything in the plant. While plant engineers often rely on point clouds or 3D models for design work, the maintenance teams are more focused on mission planning, crew scheduling and estimating materials and supplies. They can view the plant virtually, using pictures to see what they need to do and plan their work accordingly.
A second example is the use of imaging in gathering data to assist in historic preservation in a military cemetery, where records may be lost or incomplete due to accidents, the passage of time or human error. A Trimble client has developed a proposal to use the Trimble V10 to update the cemetery’s database. By using georeferenced data from the imaging rover, it’s possible to determine the location of all the tombstones in the cemetery. Using the same images, technicians can read the names and information on the individual headstones. This visual data can be attached to each grave and entered into digital records, resulting in a complete, accurate record of the cemetery.
Let’s look at one more illustration. Flooding in Colorado last year inflicted heavy damage on roads and infrastructure. Engineers and contractors needed to repair or rebuild key structures quickly and the combination of points and images provides great value in recovering from the floods. Using a Trimble V10 and Trimble R10 GNSS receiver, a team visited a rail bridge that crossed a flood-ravaged stream. They collected images from three locations around the bridge. The images went in many directions. First, technicians used Trimble Business Center software (TBC) to measure dozens of individual 3D points on the bridge. They then used the points to develop a 3D model of the bridge in SketchUp software.
Using the same images, water engineers could examine the effects of the flood scouring on the riverbed, and city planners could use the images to begin planning for reconstruction of a washed-out bike path. In addition to reconstruction, the images and measurements can assist other disciplines. Emergency managers and flood analysts can examine the river’s behavior. The flooding destroyed riparian vegetation and teams can use the data to develop plans for replanting the damaged areas. All this can come from less than one hour of field time and a small handful of images.
These examples show how—by utilizing instruments and software that integrate the work of positioning and imaging—geospatial professionals can fill in the white space between different levels of precision and data density. Completing that continuum previously required multiple technologies and techniques; today, imaging rovers make it possible with a single tool.
The Undisturbed Workflow
There are many situations when we use the tools we have because we don’t have the tools we want or need. When using an imaging rover, we have a tool that can fit more needs without sacrificing precision or performance. Consider a pipeline as-built survey, where GNSS makes quick work of locating the pipeline across long, open areas. But when the pipeline crosses a road, crews often must switch to a total station to collect extensive, detailed information on the pipeline structures, roadway, clearances and more. With the imaging rover, the crew can capture a handful of panoramas in a matter of minutes, enabling them to locate every asset on the crossing. Not only can the pipeline engineers look at a set of points—they can see the entire scene. Later in the work, some items important to the engineers can be readily measured from the photographs, potentially saving a revisit to gather the additional information.
Because the photography is integrated into the standard field workflow, the field crews could capture this crossing data without breaking stride. A single checkbox automatically captures images along with position. The Trimble V10 uses 12 separate cameras to collect photos, automatically combining the images to produce a single panoramic view. In the office, TBC allows individual panoramas to be viewed, shared and analyzed. Using the same software, it’s a simple task to measure individual points by utilizing built-in photogrammetric functionality.
With an imaging rover, it’s reasonable to expect field time to be reduced by 30 percent or more. Crews can plan their mission in the field and collect images to capture the entire scene. More and more measurement takes place in the office, further reducing costs while leaving field crews free for other tasks. And because most of the photogrammetric processes are automated into the rover and software, the system provides short learning curves in field and office.
Ultimate Flexibility—Positions From Pictures
Leveraging the power of terrestrial photogrammetry, geospatial professionals can address multiple applications. An imaging rover lets you vary your technique to achieve the accuracy and precision required for specific applications. It’s possible to quickly gather data to produce precision of 2 to 3 centimeters (0.07 to 0.1 feet), and other techniques can bring precision to sub-centimeter levels. Both approaches are very fast in providing large quantities of accurate data.
Imaging and visualization will soon be a core technology in the geospatial arena. No longer reliant on field measurements of individual points, geospatial professionals will be able to get high-accuracy results from images. Think about how you can put imaging to work for your clients. The benefits of reduced field time, increased flexibility and new deliverables can give you new opportunities and a strong competitive advantage.